Pushbutton-controlled polyphase overload circuit breaker



Aug. 9, 1966 J. ELLENBERGER PUSHBUTTON-CONTROLLED .POLYPHASE OVERLOAD CIRCUIT BREAKER Fil ed Aug. 15, 1964 FIG. 2

INVENTOR:

A JHKoB ELLENBERGER 7 Wm M United States Patent 3,265,834 PUSHBUTTON-CONTROLLED PQLYPHASE OVERLDAD CIRCUIT BREAKER Jakob Ellenberger, Nurnberg, Germany, assignor to Ellenberger & Poensgen G.m.b.H., Nurnberg, Germany Filed Aug. 18, 1964, Ser. No. 390,414 Claims priority, application Germany, Oct. 26, 1963,

E 11 Claims. (51. 200-116) The present invention relates to improvements in a pushbutton-controlled polyphase overload circuit breaker of the type as disclosed in my copending application Serial No. 275,746, filed on April 25, 1963.

The circuit breaker according to this previous application is provided, for each circuit to be controlled, with a separate bimetal strip which, when bending, permits suitable locking means to move to their inactive position while, in their active position, these locking means hold a control bridge in its connecting position. This control bridge is connected to the pushbutton, is acted upon by a release spring, and has contact bridges for the individual circuits mounted thereon in a manner so as to be insulated from each other. The locking means of this circuit breaker comprise a pivotable locking part which, in its active position, engages with a locking lever which is acted upon by all bimetal strips and is pivotable to its inactive position by any single bimetal strip. This circuit breaker is also adapted to be released by hand by means of a separate release button which is located laterally adjacent to the main pushbutton and when depressed acts upon a slide member to move the same in a direction perpendicularly to the axis of the main pushbutton, whereby the locking lever is pivoted to its inactive position.

It is an object of the present invention to improve the polyphase overload circuit breaker as above described by designing it in a manner so as to permit it to be manually released when a pull is exerted upon the main pushbutton. The additional release button and its associated elements, as were required in the circuit breaker according to the previous application referred to above, may. therefore be omitted entirely and the operation of the circuit breaker will therefore be simplified.

For attaining this object, the invention provides that for pivoting the locking lever to its inoperative position independently of the action of the bimetal strips, a rocking lever or the like is provided which is acted upon by a spring and is arrested in an inactive position against the action of this spring by a part which is connected to the pushbutton, and is released from this inactive position by a pull which is exerted upon the pushbutton.

For the purpose of simplifying the manufacture and assembly of the circuit breaker, the mentioned rocking lever may be mounted so as to rest loosely on projections on the opposite walls of the housing and it may be pressed against these projections by springs which serve primarily for the trip-free release of the circuit breaker. By employing these springs, it is therefore possible to omit additional springs. The edge of the rocking lever adjacent to these springs may then serve as its pivoting or rocking edge. The rocking lever therefore does not require a special pivot pin and associated bearing means and it may therefore be produced and installed very simply and inexpensively which, in turn, reduces the cost of the entire circuit breaker.

Another feature of the invention consists in bending the end portion of the rocking lever opposite to that ending in the rocking edge at an inclined angle relative to the other part of this lever. In the inactive position of the rocking lever, this bent-over end portion engages upon the rear side of the locking pawl which is then in 3,255,834 Patented August 9, 1966 ing the pushbutton with the control bridge when the pushbutton is depressed and the circuit breaker is thereby switched on. According to another feature of the present invention, this drive member is provided with an aperture into which a holding detent on a projection, or an upwardly bent tab of the rocking lever, engages, this tab extending parallel to the control rod. This holding detent holds the rocking lever against spring action in its inactive position. When the pushbutton is pulled toward the outside of the housing, this drive member presses the holding detent away, against the spring action, and thereby dlsengages the holding detent from the recess in the drive member and releases the rocking lever so as to pivot under the spring action. The end of the rocking lever remote from its rocking edge then acts upon the locking lever and pivots the same to its inactive position in which this locking lever also releases the locking pawl so that the latter will pivot and thereby release the control bridge from its locked position. The control bridge together with the contact bridges thereon will then move under the action of the release spring to the off position. In order to insure that the holding detent of the rocking lever will properly disengage from the recess in the drive member, the holding detent is rounded.

According to another feature of the invention, the control bridge is provided with a bar of insulating material to which the outer contact-bridge supports are removably secured. For simplifying the manufacture and assembly of the circuit breaker, the outer contact-bridge supports are inserted into a slot in the insulating bar and are secured therein by a springloaded locking member which engages into a recess in the contact-bridge support. This locking member engages into the recess in the contactbridge support and may consist of a holding detent which is pressed out of the bottom of a cup-shaped member which contains a compression spring. This cup-shaped member may be formed, for example, of a cross-shaped stamped part with a central bottom, and arms thereon which are bent over toward one side so as to project at right angles to the bottom. This structure may be easily manufactured and assembled.

The above-mentioned as well as numerous additional features and advantages of the present invention will become more clearly apparent from the following detailed description thereof which is to be read with reference to the accompanying drawings, in which:

FIGURE 1 shows a side view of an opened circuit breaker according to the invention, in the on position;

FIGURE 2 shows the same view of the circuit breaker in the off position;

FIGURE 3 shows a view of the circuit breaker as seen from the right of FIGURE 1, a part of the housing being broken away to disclose the inside thereof;

FIGURE 4 shows a bar of insulating material which is secured to the control bridge and carries the contact bridges, as seen from the left of FIGURE 1;

FIGURE 5 shows a cross section of the insulating bar according to FIGURE 4 and of one of the contact bridges thereon;

FIGURE 6 shows an enlarged cross section of a part of FIGURE 5; while FIGURE 7 shows a view of the part according to FIGURE 5, as seen from the left thereof.

As illustrated in the drawings, the housing of the polyphase overload circuit breaker according to the in assessavention consists of two central parts 1 and 2 and coverlike lateral parts 3 and 4, all of which are made of molded insulating material. These housing parts 1 to 4 interengage with each other by means of corresponding projections and recesses so that all of them may be firmly connected to each other by a single screw or rivet which is inserted through a bore '7. The housing has outwardly projectingtherefrom a pushbutton 8 by means of which the circuit breaker may be switched on as well as off by hand. Each of the two central housing parts 1 and 2 has acentral partition so that, between these partitions,

a control or quenching chamber is formed in which the movable mechanism of the circuit breaker is located,

which is illustrated particularly in FIGURES 1 and 2.

The outer walls of the lateral covers 3- and 4' and the side walls of the two central parts 1 and 2 define two further control or quenching chambers. These three chambers contain the control and connecting elements for three separate circuits. For each of these circuits, a terminal strip 10 is provided which has a connecting screw 11 and a fixed contact 12 on its opposite ends.

This contact 12 may be connected by a contact bridge 13 to a further fixed contact 14 on one end of a contact bar 15 which, in turn, is connected to a bimetal strip 16 and forms with the latter a structural unit which is inserted as such into a suitable recess in the associated housing part and is secured therein by a screw 17. The contact bar 15 carries a setscrew 18 the tapered end of which engages upon a ceramic member 20 which is guided in slots in the housing parts and acts upon the 'bimetal strip 16. While the bimetal strip 16 may be heated either directly or indirectly, it is illustrated in FIGURES l and 2 as being heated directly and as having a U-shaped cross section at its lower end, one arm of the U being connected to the contact bar 15 and the other arm to a bent part 19 of a terminal strip 22 which carries a connecting screw 11 on its lower end.

Allthree bimetal strips 16 act upon an insulating bar 23 which is secured to a locking lever 24. This locking lever 24 is pivotable about a pin 25 which passes through corresponding bores in a pair of bent-over tabs 25' on lever 24 and the ends of this pin 25 are inserted into corresponding blind holes in the two outer housing parts 3 and 4. As shown in FIGURE 3, the locking lever 24 has two projections 26 and 27 at its center. The projection 26 extends through an aperture 28" in a locking pawl 28, while the projection 27 engages upon a part 23' of pawl 28. Pin 25 carries a torsion spring 44 one end of which engages upon the projection 26 on the locking lever 24, while its other end engages upon the pawl 28.

This pawl 28 is pivotably mounted on a pin 27 the ends of which are inserted into blind holes in the two central housing parts 1 and 2. Pawl 28 has a locking detent 29 and a stop projection 30. As shown in FIG- URE l, the lockingdetent 29 is adapted to lock a control bridge 31 in its connecting or on position. Control bridge 31 is acted upon by two compression springs 32 the lower ends of which rest on a rocking lever 33. This rocking lever 33 rests loosely on a pair of projections on the two central housing parts 1 and 2 and it is held in this position by the action of the compression springs 32. The left outer edge of the rocking lever 33 as shown in FIGURE 1 forms the rocking edge of this lever. Rocking lever 33 is bent over twice and its outer apex is adapted to act upon the insulating bar 23 and thus upon the locking lever 24. When the circuit breaker is in the on position as shown in FIGURE 1, the right upper end of the rocking lever 33 engages upon the rear side of the pawl 28. In this position, one arm of the rocking lever 33 therefore rests with its left edge on the housing projections 34, while its other arm rests on the rear side of the pawl 28.

Rocking lever 33 which forms a stamped part and the angular parts of which are recessed is further provided on its lower arm with a 1.41 35 which extends in the direction 4 toward the pushbutton 8 and has \a detent 35 pressed out of its upper end. When the circuit breaker is in the on position according to FIGURE 1, this detent 35 engages into a corresponding aperture in one arm 41 of a U- shaped drive member 37 which is secured to the lower end of the control rod 36 which is rigidly connected to the pushbutton 8. The other arm 38 of this drive member 37 is adapted to engage with a detent 39 on the central contact-bridge support 46 of the control bridge 31 which carries on its lower end a contact bridge 13. The arm 41 of the drive member 37 is extended perpendicularly to the plane of FIGURES 1 and 2 in both directions and r is guided in vertical grooves in the adjacent partitions of the central housing parts 1 and 2. Control rod 36 is guided in an aperture in an insulating washer 42 of hard paper which is inserted into the bottom of the housing recess in which the pushbutton 8 is movable. rod 36 carries a release spring 43' one end of which rests on the insulating washer 42, while its other end presses against the pushbutton 8.

The control bridge 31 carries a bar 70 of insulating material which is rigidly secured thereto and carries the central contact-bridge support with the contact bridge 13 thereon. The two outer contact-bridge supports 40' are inserted into slot-shaped apertures 71 in the insulating bar 70 up to the engagement of their shoulders against the edges 72, as shown in FIGURE 5; and they are secured in this position by a cup-shaped member 73 and a compression spring 74 therein. This cup-shaped member 73 is cross-shaped and its four arms 75 are bent over toward the left, as shown in FIGURE 6. The bottom 76 of member 73 has an outwardly pressed detent 77 which engages into an aperture in the contact-bridge support 40'. The cup-shaped member 73 and the compression spring 74 therein are inserted into a recess 78 adjoining the slot 71 in the insulating bar 70. During the assembly of the circuit breaker, the contact-bridge support 40 is first inserted into the slot 71 and thereafter the cup-shaped member 73 with the compression spring 74 is inserted into the recess 78 in a manner so that the detent 77 engages into the corresponding aperture in the which this detent was previously engaged. The rocking lever 33 is thus released and by the action of the compression springs 32 it will then be pivoted about its rocking edge from the position as shown in FIGURE 1 in the clockwise direction. The upper apex of the rocking lever 33 is thereby pressed against the insulating bar 23 on the locking lever 24 so that the latter is pivoted to its inactive position and thereby releases the pawl 28 to permit the same to pivot likewise to its inactive position. Under the action of the release spring 43 and the springs 32, the control bridge 31 is then moved by the drive member 37 to the off position in which it engages upon an inclined stop 63 on the two central housing parts 1 and 2.

When the pushbutton 8 is depressed and the circuit breaker is thereby switched on, the arm 38 of the drive member 37 takes along the control bridge 31 by engaging with the detent 39. The right end of the control bridge 31 then hits against the projection 30 on pawl 28 the rocking lever 33 is pivoted by the release spring 43 against the action of the springs 32 in the counterclock- Control 7 wise direction to the inactive position as shown in FIG- URE 1.

Although my invention has been illustrated and described with reference to the preferred embodiment thereof, I wish to have it understood that it is in no way limited to the details of such embodiment but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim is: 1. A pushbutton-controlled polyphase overload circuit breaker comprising a housing, a plurality of bimetal strips in said housing, each of said strips being located in a separate circuit, a locking lever pivotally mounted in said housing and acted upon by all of said bimetal strips and pivoted to its inactive position by any single bimetal strip, a pushbutton slidable in said housing, a control bridge movably mounted in said housing and interconnected with said push-button when the latter is depressed to the on position, a pawi pivotally mounted in said housing and engaging and locking said control bridge in the on position, a release spring biasing said control bridge toward the off position, a plurality of contact bridges secured to said 2. An overload circuit breaker as defined in claim 1,-

rurther comprising projections on the opposite walls oi said housing, said rocking lever resting 'loosely on said projections, and spring means for the trip-tree release of said circuit breaker and pressing said rocking lever against said projections to maintain the same thereon.

'3. An overload circuit breaker as defined in claim 2,

wherein the edge of said rocking lever adjacent to said spring means forms the rocking edge oi said lever.

'4. An overload circuit breaker as defined in claim 3, wherein the end portion otf said rocking lever opposite to the end terminating in said rocking edge is bent over at an angle and, when said rocking lever is in its inactive position, said end portion resting on the rear side of said pawl which is then in its locking position.

5. An overload circuit breaker as defined in claim 4, wherein said rocking lever storms a stamped part and said bent-over end portion of said lever is notched out so as to [form two arms which, when the circuit breaker is switched on, rest on the rear side ofsaid pawl which is then in its 'locking position.

6. An overload circuit breaker as defined in claim 1, [further comprising a control rod rigidly connected at its upper end to said pushbutton, a drive member secured to the lower end of said control rod and operable to interconnect said pushbutton with said control lbridge, said rooking lever having an upwardly bent part thereon extending substantially parallel to said control rod and having a holding detent thereon which, when said circuit breaker is switched on, engages into a corresponding aperture in said drive member.

7. An overload circuit breaker as defined in claim 6, wherein said holdin-g detent on said upwardly bent part of said rocking lever is rounded.

8. An overload circuit breaker as defined in claim 1, rfiurther comprising a bar of insulating material secure-d to said control bridge, and means removably securing the outer contact bridges to said insulating bar.

9. An overload circuit breaker as defined in claim 8, wherein said insulating bar has at least one slot therein, said securing means [for said outer contact bridges being inserted into said slot, a locking member, and a spring acting upon said locking member, said locking member and said spring being inserted into an aperture in said insulating bar, said locking member under the action of said spring engaging into an aperture in said securing means and thus removab ly securing said securing means in said slot.

10. 'An overload circuit breaker as defined in claim 9, wherein said locking member consists oi a cup-shaped member having a bottom and a detent pressed outwardly [from said bottom, said spring tforming a compression spring inserted into said cup-shaped member and pressing said detent into said aperture in said securing means.

11. An overload circuit breaker as defined in claim 10, wherein said cup-shaped member consists of a cross-shaped stamped part having a central portion and arms thereon bent over toward one side so as to extend perpendicularly to said central portion forming said bottom.

N 0 references cited.

- BERNARD A. GILHEANY, Primary Examiner. 

1. A PUSHBUTTON-CONTROLLED POLYPHASE OVERLOAD CIRCUIT BREAKER COMPRISING A HOUSING, A PLURALITY OF BIMETAL STRIPS IN SAID HOUSING, EACH OF SAID STRIPS BEING LOCATED IN A SEPARATE CIRCUIT, A LOCKING LEVER PIVOTALLY MOUNTED IN SAID HOUSING AND ACTED UPON BY ALL OF SAID BIMETAL STRIPS AND PIVOTED TO ITS INACTIVE POSITION BY ANY SINGLE B IMETAL STRIP, A PUSHBUTTON SLIDABLE IN SAID HOUSING, A CONTROL BRIDGE MOVABLY MOUNTED IN SAID HOUSING AND INTERCONNECTED WITH SAID PUSHBUTTON WHEN THE LATTER IS DEPRESSED TO THE ON POSITION, A PAWL PIVOTALLY MOUNTED IN SAID HOUSING AND ENGAGING AND LOCKING SAID CONTROL BRIDGE IN THE ON POSITION, A RELEASE SPRING BIASING SAID CONTROL BRIDGE TOWARD THE OFF POSITION, A PLURALITY OF CONTACT BRIDGES SECURED TO SAID CONTROL BRIDGE AND INSULATED FROM EACH OTHER, EACH OF SAID CONTACT BRIDGES BEING ASSOCIATED WITH ONE OF SAID BIMETAL STRIPS, A ROCKING LEVER ENGAGING SAID LOCKING LEVER AND OPERABLE TO PIVOT THE LATTER TO ITS INACTIVE POSITION INDEPENDENTLY OF THE ACTION OF SAID BIMETAL STIRPS, SPRING MEANS ACTING UPON SAID ROCKING LEVER, A MEMBER CONNECTED TO SAID PUSHBUTTON AND HOLDING SAID ROCKING LEVER IN ITS INACTIVE POSITION AGAINST THE ACTION OF SAID SPRING MEANS; SAID LAST-NAMED MEMBER RELEASING SAID ROCKING LEVER WHEN A PULL IS EXERTED UPON SAID PUSHBUTTON. 